Today, the network was congested again. The transaction I submitted was queued in the mempool, and I started to doubt my life... Basically, clicking send ≠ immediate on-chain confirmation. It first waits in the "waiting room" for miners/validators to pick, and if the fee isn't high enough, it just gets left hanging, or even possibly "cut in line" by a higher fee from the same transaction. The most annoying part is thinking you've completed the operation, only to regret and want to change it a few minutes later, but the chain doesn't really give you any dignity.